SD 



P415S 



8 



Issued July 22. 1911. 

U. S. DEPARTMENT OF AGRICULTURE, 

FOREST SERVICE— BULLETIN 94. 

HENRY S. GRAVES, Forester. 



SCRUB PINE. 



Pin us vmiiniana.) 



W. D. STERRETT, 



FOREST ASSISTANT. 





WASHINGTON : 

GOVERNMENT PRINTING OFFICE. 

1911. 




Pass S T)3B7 
Book i 



^ C/ 



Jul. 94, Forest Service, U. S. Dept. of Agriculture. 



Frontispiece. 







i^^'jif^>ta*.'^^^' 



,?<'-< ::*- ^• 




Fig. 1 .—Twenty-five to Thirty Year Old Stand Clean Cut for Fuel, Yielding 
ABOUT 30 Cords per Acre. 




Fig. 2.— Forty-five to Fifty Year Old Stand Clean Cut for Box Boards, Yielding 
20,000 Feet of 1-inch Boards per Acre. Characteristic Persistence of Limbs, 
Resulting in Low-grade Lumber. 

PURE, EVEN-AGED, WELL-STOCKED STANDS OF SCRUB PINE. 



If- 



Issued July 22, 1911. 



U. S. DEPARTMENT OF AGRICULTURE, 
FOREST SERVICE — BULLETIN 94. 

HENRY S. GRAVES, Forester. 



SCRUB PINE. 



(Pinus virginiana.) 



. D. STERRETT, 

FOREST ASSISTANT. 




WASHINGTON : 

GOVERNMENT PRINTING OFFICE. 

1911. 



Cy^-)^^ 



'X ^"^ 



-o"^ -^ 



c^V 



LETTER OF TRANSMITTAL 



United States Department of Agriculture, 

Forest Service, 
WasJiington, B.C., Aj^ril 5, 1911. 
vSir: I have the honor to transmit herewith a manuscript entitled 
"Scrub Pine," by W. D. Sterrett, Forest Assistant, and to recommend 
its pubHcation as Bulletin 94 of the Forest Service. 
Respectfully, 

Henry S. Graves, 

Forester. 
Hon. James Wilson, 

Secretary of Agriculture. 
2 



CONTENTS 



Paga 

Introduction 5 

Nomenclature 5 

Distinguishing characteristics 5 

Distribution and occurrence 6 

Distribution in the different States 6 

Virgin forest 7 

Second growtJi 8 

Form and development 8 

Open stands 8 

Dense stands 9 

Growth of fully stocked stands 9 

Growth of single trees 10 

Reproduction 11 

Production of seed 11 

Dissemination of the seed 12 

Germinating capacity of the seed 12 

Germination and seedling establishment 13 

Seedling development 13 

Enemies 14 

Fire 14 

Wind 15 

Insects 15 

Fungi ■ 16 

Characteristics of the wood 16 

Appearance 16 

Mechanical properties 17 

Seasoning 17 

Durability 17 

Suitability for chemical fiber and ground-wood pulp 18 

Uses and market 18 

Advisability of forest management : 20 

Purposes of management and rotation 21 

Sustained annual yield 22 

New crops by natural reproductii-n 22 

Improvement thinnings 24 

Protection 25 

Extension 25 

Prevention of extension 26 

Summary - 26 



LLUSTRATIONS. 



Fig. 1. — Twenty-five to thirty-year-old stand clean cut for fuel, yielding about 
30 cords per acre. Fig. 2. — Forty-five to fifty-year-old stand clean 
cut for box boards, yielding 20,000 feet of 1-inch boards per 

acre Frontispiece. 

3 



SCRUB PINE. 



INTRODUCTION. 

Scrub pine yields only inferior timber, but the abundance of the 
tree, especially as second growth on old fields and waste land, the 
ease with wliich it reproduces itself, and its ability to thrive on sterile 
soils, such as clays and marls, where no other species will grow, make 
it important throughout its commercial range. It offers an impor- 
tant problem of woodlot management in several eastern States, espe- 
cially in Maryland and Virginia, wdiere it has taken possession of 
many thousands of acres of idle farm land. 

NOMENCLATURE. 

The botanic name of scrub pine is Pinus virginiana (Mill). The 
species has a dozen or more common names, of which the most fre- 
quently used after scrub pine are spruce pine and jack pine. It is 
called spruce pine mostly in the Coastal Plain region, where it grows 
with loblolly, while in the mountains, where it grows with wliite pine, 
it is usually known as jack pine. The species is also known by the 
following names in various parts of the country: Jersey pine, short- 
shucks or shortshat pine, shortleaved pine, cedar pine, river pine, 
nigger pine, oldfield pine, bastard pine, second-growth pine, and pov- 
erty pine. Often it is known by several names in one locality, 
according to its presence as small second-growth or as large and 
mature trees. 

DISTINGUISHING CHARACTERISTICS . 

Scrub pine can readily be distinguished from the other 3^ellow pines 
by its general appearance and b}^ its leaves, cones, and bark. Two 
needles are borne together in a sheath; they are from 1 to 2 J inches 
in length, always have a decided twist, and are only slightly rigid. 
The cones are broad and sessile and from 1| to 2^- inches in length. 
Many cones cling to the trees for several years after shedding their 
seeds, so that frequently a tree is covered, with cones of different 
ages. The bark of the tree is thin, scaly, and much thinner than that 
of most yellow pines. Even on the largest trees it is very seldom 
as much as three- fourths of an inch tliick, and usually less than one- 
half inch. On the trunks of small poles it is one-eighth to one-fourth 
inch in thickness. It is dark brown in color, with a slightly reddish 
tinge, and it is divided by shallow fissures into thin, scaly plates. On 

5 



6 SCRUB PINE. 

large trees the fissures in the bark of the trunk are rather wide and 
deep, and the bark in the crowns is smooth and a yellowish red. 

Pitch, loblolly, and shortleaf, the pines wliich are most frequently 
associated with scrub pine, are easily distinguished from it. Pitch 
and loblolly pines have three needles in a sheath, and their needles 
and cones are much longer; shortleaf has smaller cones and two or 
three needles, which are somewhat longer than those of scrub pine, 
rigid and straight, and lack the characteristic twist of scrub pine. 

DISTRIBUTION AND OCCURIIENCE. 

The natural range of scrub pine is from Staten Island in New York 
to Blount and Winston Counties in northern Alabama and from the 
Atlantic coast to southern Indiana. In the northern part of its 
range it is found near the coast, but southward it grows at a con- 
stantly increasing distance from the sea, until, in northern Alabama, 
it occurs only in the mountains. 

Its natural range indicates that scrub pine is best adapted to cli- 
mates where the thermometer seldom falls below zero in winter or 
rises above 100° F. in summer, where the growing season is not 
extremely long, and where there is abundant rainfall combined with 
a high average humidity. 

It is not adapted to a very sandy soil, such as dunesands along the 
coast. It thrives best on a clay or loam, or a sandy loam. It is pos- 
sible to extend the range of scrub pine considerably farther north or 
south. It has, for example, been grown in the Arnold Arboretum 
in Cambridge, Mass., where it has borne good seed. It is excluded 
from certain climates to the South not unfavorable to its growth 
largely by the competition of other species still better adapted to those 
climates. 

DISTRIBUTION IN THE DIFFERENT STATES. 

In New York scrub pine grows on Staten, Long, and Middle Islands, 
but never in pure stands of commercial importance. In New Jersey 
the species occurs scatteringly through the southern two-tliiirls of the 
State, where it occasionally forms pure groves of small extent, espe- 
cially in Cumberland County. Its occurrence in the State is princi- 
pally on the central Cretaceous formation, where the soils consist of 
marls, clays, and sandy clays. In tliis section of the State scrub 
pine and shortleaf pine are the most common coniferous trees. Scrub 
pine has been noticed as far north as Union, Somerset, and Hunter- 
don Counties, where the geological formation is Triassic and the 
underlying rocks are red sandstone, shale, and trap. On the area of 
very sandy soil in southeastern New Jersey scrub pine does not occur, 
and pitch pine is the prevailing tree. 

Scrub pine has a botanical range through the southern half of 
Pennsylvania, where it occurs naturally on sterile tops of hills and 
ridges less than 1,000 feet in elevation. In several localities it has 



DISTRIBUTION AND OCCUEEENCE. 7 

taken possession of abandoned farm land, and forms pure groves of 
some extent. It is not commercially important for lumber, owing to 
its small size and limited quantity. Its principal uses in the State 
are for mine props and lagging and for pulp wood. 

The species occurs in all three counties of Delaware, but in com- 
mercial quantities only in the southwestern corner of Kent County 
and in the western portion of Sussex. It has some slight commercial 
importance for lumber in this State. 

In Maryland scrub pine has considerable commercial importance. 
It is found in all the counties of the State. It grows, to some extent, 
in the original forest, but its predominating growth is on the old 
fields. This old-field growth is most abundant in Charles, St. Marys, 
Prince Georges, Anne Arundel, Caroline, and Dorchester Counties. 
The second growth is used chiefly for fuel, box boards, pulp wood, and 
charcoal, and the old growth for lumber. 

In Virginia and North Carolina scrub pine is found in the Pied- 
mont Plateau region and in the mountains below an elevation of 
3,000 feet, but in the Coastal Plain region it occurs only in the north- 
ern part of Virginia. It frequently forms pure stands of considerable 
extent on abandoned fields. In second-growth it tends to supplant 
shortleaf pine in the Piedmont region and white pine in the moun- 
tains. These stands are extensive and are becoming of considerable 
commercial importance. 

In West Virginia it can be found in every count}^ and wdierever 
there is pine. It is seldom large enough for lumber, but is extensively 
used for fuel and mine props. 

The northern and mountainous part of South Carolina, Georgia, 
and Alabama forms the southern limit of the range of the species. 
Here it has, for the most part, only a scattered botanical distribu- 
tion, and is not commercially important. It has an extensive range 
in Tennessee and Kentucky, and is found in all but the western fourth 
of these States. It is here of some commercial importance for fuel 
and rough lumber for local uses. It grows also in the southeastern 
corner of Indiana and in the southern half of Ohio, only occasionally 
reaching dimensions suitable for saw timber. 

VIRGIN FOREST. 

In virgin forests tliroughout its range scrub pine grows almost 
exclusively on the least fertile soils and m dry, exposed situations. 
The natural sites for the species seem to be on sterile clay soils and 
on gravelly and sandy land. It occurs in two types of virgin forests, 
(1) on dry pine ridges, in mixture with other pines, and (2) on dry 
southern and western exposures, in mixture with hardwoods and 
other pines. On account of its comparatively slow growth after it 
has reached an age of 50 or 60 years, its short life, and its intolerance 
of shade, it is seldom found on the better sites in the virgin forest. 

. 91503°— Bull. 94—11 2 



8 SCRUB PINE. 

After a severe windfall on a good site the area may be seeded up to 
scrub pine. But the type thus formed is temporary; the scrub pine 
will eventually be crowded out and the original type reestablished. 
The species can hold its own only on the poorer sites, to which it is 
especially adapted, and on this account it never forms extensive pure 
stands in the virgin forests. Wliere it occurs in the pine-ridge type it 
sometimes constitutes more than 50 per cent of the stands, while in 
the mixed hardwood and pine type it seldom forms over 25 per cent. 

SECOND GROWTH. 

The variety of sites on which scrub pine occurs, as well as the total 
area of land occupied by the species, has been greatly increased by the 
interference of man in the cullmg and clearmg of forest land. This 
is due to its superior reproductive power, which results m the increase 
of the proportion of scrub pine after lumbermg, especially where the 
logging is close. Even where there is no scrub pine in the original 
mixture, severely logged hardwood and white pine slopes are often 
seeded up to scrub pine from seed trees situated on the pine ridge 
above. The proportion of scrub pine in the second growth which 
follows logging is usually greater than in the origmal forest, yet it 
never succeeds in forming large pure stands on lumbered areas. 
Fires immediately after lumbering tend to favor the reproduction 
and to increase the proportion of scrub pme m the new growth, but 
coming later are likely to be very destructive to seedlings already 
established. 

The species reproduces best on abandoned farm land and there 
forms extensive pure stands. The second growth on old fields is of 
more importance than the original growth in virgin or culled forests, 
because it is greater in amount. This old-field growth has sprung up 
on farm land abandoned durmg and since the Civil War, and most of 
it is under 50 years old. 

FORM AND DEVELOPMENT. 

Scrub pine under 15 years in age normally has a long, regular, nar- 
row, conical crown, and a straight undivided stem covered with 
branches nearly to the ground. With advancing age the lower 
branches die and drop off and the crown gradually becomes shorter 
and wider — first broadly conical, then rounded, and finally short, 
flat, broad, and irregular. Its form is dependent prmcipally on the 
age of the individual tree and the density of the stand in which it has 
grown. It is also affected by the quality of the soil on which the 
tree is growing. 

OPEN STANDS. 

Where the stand is so open that the trees receive full sunlight on 
all sides, they develop wide-spreading, thick-branched, low crowns 



FORM AND DEVELOPMENT. 



9 



nearly as broad as the trees are high, and very short trunks. Such 
trees are useful only for cordwood or for protecting the soil. They 
make prolific seed trees, and several of them on an acre of unused 
farm land will furnish seed for a dense growth. 

DENSE STANDS. 

It is desirable to develop trees which at maturity will be tall, with 
straight, clear, smooth boles, and dense, even-aged stands will pro- 
duce this form. The greater the density of the stand the more desir- 
able is the form of each tree in it. The constant suppression of the 
lower branches concentrates the growing energy of the tree in its 
terminal shoot, so that the maximum height growth is attamed. 
Scrub pine is inferior to most other yellow pines m self-pruning 
ability, so that density of stand is especially necessary. 

GROWTH OF FULLY STOCKED STANDS. 

A large part of the old-field growth of scrub pine consists of dense, 
fully stocked stands, practically even aged, and almost pure. Such 
stands, and the individual trees composmg them, have a normal and 
regular growth. 

Stands not fully stocked show great variations in yield, according 
to the degree of density. To secure the best development scrub-pine 
stands must have enough seedlings, and evenly enough distributed, 
so that the stand will be closed up when from 6 to 8 years old — that 
is, the crowns touching each other on all sides and the ground fairly 
well shaded. 

Table 1 shows the average development and yield of fully stocked 
stands on old fields in Maryland. 

Table 1. — Stand and yield per acre at different ages, Montgomery and Prince Georges 

Counties, Md} 



Age. 


Number of trees per acre. 


Yield per acre. 


Total. 


Trees 5 

to 9 

inches 

diameter, 

breast 

high. 


Trees 10 

inches 

and over 

diameter, 

breast 

high. 


Includ- 
ing top 

and 
stump. 


Firewood. 


Pulp 
wood. 


Trees 5 

inches 

and over. 


Years. 

10 

15 

20 

25 

30 

35 

40 

45 

50 


3,790 
2, 510 
1,470 
885 
025 
490 
420 
380 
370 






Cubic feet. 


Cords. 


Cords. 


Boardft. 


CO 
275 
3S0 
395 
370 
330 
290 
250 




1,2S0 
2,010 
2,510 
2,990 
3.450 
3,900 
4,290 
4,650 


12.8 
20.1 
25.1 
29.9 
34.5 
39.0 
42.9 
40.5 




720 
5,790 
9,590 
11,850 
13,600. 
15,070 
16.440 
17,700 










5 
25 

45 
70 
90 


2G,0 
30.0 
33.9 
37.3 

40.4 



' This table is based on 39 sample plots that averaged one-third of an acre each . The yield in cords was 
calculated from the yield in cubic feet, 1 cord of firewood lieing computed to be equal to 100 cubic feet and 
1 cord of pulp wood equal to 115 cubic feet. The boarii-feet measurements were obtained by scaling trees 
5 inches and over, breast-high diameter, by a mill tally table for white pine, subtracting 10 per cent, and 
plotting a curve. 



10 



SCRUB PINE. 



The table shows how the number of trees m the stand decreases 
with increase in age. At 80 years, stands with more than 100 trees 
to the acre are rare, and at this age the stand has become uneven 
and undergrown with hardwoods. 



GROWTH OF SINGLE TREES. 

The growth of single trees in diameter, height, and volume varies 
with age, the amount of growing space, and the quality of the site. 
In open stands the rate of diameter grov/th is more rapid than in 
dense stands, but a lesser height growth is attained and the volume 
growth for the whole stand is usually less, while the timber is far 
inferior in quaUty. Table 2 shows the rate of growth in diameter, 
height, and volume of average dominant trees in fully stocked 
stands. 

Table 2. — Groivth of trees on old fields in Montgomery and Prince Georges Counties, Md. ^ 



Ago. 


Average 

diameter, 

breast 

high. 


Maximum 
diameter, 

breast 

high. 


Height. 


Total 
vokune. 


Age. 


Average 

diameter, 

breast 

high. 


Masimum 
diameter, 

breast 

high. 


Height. 


Total 
volume. 


Years. 
5.... 
10.... 
15.... 
20. . . . 
25. . . . 
30.... 


Inches. 
0.4 
2.4 
3.8 

4.8 
5.7 
6.5 


Inches. 
0.8 
3.8 
5.6 
6.8 
7.8 
S.6 


Feet. 
6 
17 
26 
33 
40 
46 


Cu.ft. 

""q.'2" 
1.0 
2.5 
4.3 
6.2 


Years. 
35. . . . 
40. . . . 
45. . . . 
50.... 
55. . . . 
60. . . . 


Inches. 
7.2 
7.8 
8.4 
9.0 
9.6 
10.1 


Inches. 
9.4 
10.1 
10.8 
11.4 
12.1 
12.8 


Feet. 
51 
55 
59 
63 


Cv.ft. 
8.4 
11.1 
14.4 
18.4 
23.1 







1 Basis: 104 average dommant trees selected from 39 sample plots. 

Single trees grown in dense stands sometimes reach the dimensions 
of good-sized timber trees. The species, as a rule, is short lived, and 
150 years is about its age limit. Three feet in diameter and 125 feet 
in height may be considered the maximum dimensions attained by 
the species, but trees more than 18 inches in diameter and 100 feet 
high are rare. 

Tables 3, 4, and 5 show the merchantable volume of scrub pine in 
board feet, in fuel cords, and in cords of peeled pulp wood. 

Table 3. — Merchantable volume of scrub pine, in board feet, Montgomery and Prince 

Georges Counties, Md. ' 



Diam- 
eter, 
breast 
high. 


Height. 


VolLune. 


Diam- 
eter, 
breast 
high. 


Height. 


Volume. 


Diam- 
eter, 
breast 
high. 


Height. 


Volume. 


Inches. 
5 
6 

7 
8 


Feet. 
43 

47 
50 
52 


Boardft. 

11 
21 
32 

44 


Inches. 
9 

10 
11 
12 


Feet. 
54 
56 

58 
60 


Boardft. 
57 
73 
91 

112 


Inches. 
13 
14 
15 


Feet. 
61 
63 
65 


Boardft. 
136 
163 
194 



' Equivalent to actual saw cut, since it was obtained by scaling trees of average heif,'ht by Margolin's 
mill tally table for white pine, subtracting 10 per cent, and plotting a curve. This table is based on meas- 
urements of 242 trees. 



REPRODUCTION. 11 

Table 4.- — Volume of scrub pine m fuel-wood cords, Maryland.^ 



Diame- 
ter, 
breast 
high. 


Height (feet). 


10 


15 


20 


25 


30 


35 


40 


45 


50 


55 


60 


65 


70 


75 


Volume (cords). 


Inches. 

2 

3. ... 


0.002 


0.003 


0.003 
,006 


0.004 
.007 






















0.009 
.015 
.022 


0.010 
.017 
. 026 
.037 
.050 


0.012 
.020 
.029 
.0-12 
.057 
.075 
















4 






0.022 
.033 
.047 
.064 
.085 
.105 
.129 


0.024 
.036 
.052 
.072 
.094 
.116 
.141 
.168 












5. . 










0.040 
.057 
.079 
.103 
.128 
.154 
.182 
.210 










6 










0.063 
.087 
.133 
.139 
.166 
.196 
.226 


0.068 
.094 
.122 
.151 
.179 
.210 
.241 






7 












0.102 
.131 
.162 
.192 
.225 
.257 


0.174 
.204 
.238 
.271 


8. 












9 














10 
















11.. 
















12 







































1 Basis: 228 trees. To get the volume of the entire stem in solid cubic feet, including bark, stump, an'' 
top, and excluding branches, multiply the number of cords in each case by 100. 

Table 5. — Volume of scrub pine in cords of peeled pulp wood, Maryland.^ 



Diameter, 
breast 
high. 


Height (feet). 


30 


35 


40 


45 


50 


55 


60 


65 


70 


75 


Volume (cords). 


Incites. 

4 

5 

6 


0.013 
.019 


0.015 
.023 
.032 
.043 


0.017 
.025 
.037 
.050 
.065 


0.019 
.029 
.041 
.056 
.074 
.091 
♦ .112 


0.021 
.031 
.045 
.063 
.082 
.101 
.123 
.146 












0.035 
.0.50 
.069 
.090 
.111 
.134 
.158 
.183 










0.055 
.076 
.098 
.121 
.144 
.170 
.197 


0.060 
.082 
.106 
.131 
.156 
.183 
.210 










0.089 
.114 
.141 
.167 
.196 
.224 


0.151 
.177 
.207 
.236 


8 




9 






10 








11 








12 























1 Basis: 228 trees. 



REPilODUCTION. 



The reproductive power of scrub pine is its most important silvical 
characteristic. It reproduces itself with the utmost ease, even on 
the poorest soils, and for this reason it has been able to hold its own 
in competition \\ith faster-gromng and longer-lived species with 
which it is associated. This superior reproductive power, even on 
sterile situations, is what recommends it as sometimes desirable for 
forest managment. 

PRODUCTION OF SEED. 

The seeds of scrub pine are ripe in November of the second year, 
and fall from the cones during the early part of the followmg. winter. 

The species is very prolific in seed bearing and the trees in the open 
may bear cones when 5 years old. Isolated trees in old fields bear 
abundant good seed ahnost annually from the age of 10 years. In 



12 SCRUB PINE. 

general abundant seed is produced every year over the entire range 
of the species. Very httle seed is borne by young trees growing in 
thick, dense stands. But by the time such stands have reached 
50 years the canopy has become broken, the crowns are isolated, and 
the trees bear many cones. It is important to note that border trees 
in dense stands, which receive much side light and have more crown- 
growing space, are good seed-producing trees; also, that if a dense 
stand be heavily thinned the trees remaining will produce abundant 
seed within two or three years. 

DISSEMINATION OF THE SEED. 

The natural dissemination of pine seed takes place principally 
through the agency of the wind, and to a slight extent through birds, 
annuals, and water. The ripened cones open up in early winter, and 
the winged seeds drop out and are scattered by the wind. A tree 
with abundant cones will scatter its seeds plentifully to a distance of 
twice its own height, and sometimes seed is disseminated to a distance 
of a quarter of a mile in the direction of the prevailing wind. The 
nature of the dissemination is well illustrated where pine seed trees 
are situated along the edge of unused cleared land. Next the trees 
abundant reproduction takes place for from 50 to 100 feet; at from 
100 to 300 feet the reproduction is still fairly uniform, but is very 
open; and beyond 300 feet it is very irregular and widely separated. 

GERMINATING CAPACITY OF THE SEED. 

The percentage of fertile seeds is ver;^ high. Prof. J. W. Tourney, 
who has experimented with the species in the nursery of the Yale 
Forest School at New Haven, Conn., says: 

In the seed bed we have found no difficulty in the germination oi this species. 
So far as germination is concerned, it might be termed one of the pine weeds, as this 
species, jack pine (Pinus divaricata), and loblolly pine germinate with the greatest 
uniformity and the highest germinating per cent of all the pines I have ever grown. 

The high germinating capacity is possessed by seeds produced by 
trees from the time they are only 10 years old until they are over- 
mature and declining. 

The seed sometimes retains its vitality for several years after falling 
to the ground. Prof. S. C. Mason, of Berea College, Kentucky, cites 
a case in which a piece of ground cleared of scattering pines and left 
undisturbed had four years later 100 to 200 seedlings to the square 
rod (or 16,000 to 32,000 to the acre), from 1 to 4 years of age. Since 
there were no seed trees within less than 200 yards of the area, and 
these were to the leeward of the prevailing winds, it can not be 
doubted that the 1 to 4 year seedlings in this case sprang almost 
exclusively from seeds which fell four and more years previously. 



REPRODUCTION. 13 

Seeds collected from the trees and preserved under favorable con- 
ditions will retain their vitality from 5 to 10 years, though the per- 
centage of germination will decrease with the age of the seed. 

GERMINATION AND SEEDLING ESTABLISHMENT. 

In the dense forest conditions may be favorable to seed germina- 
tion, but the lack of light precludes seedling development, and scrub 
pine seedlings which become established will not survive more than 
a year or so unless the forest is opened up. On the other hand, under 
the canopy of a broken stand the reproduction is often excellent. 
The moisture conditions are there especially favorable to germination, 
while there is also sufficient light for seedling growth. Germination 
takes place readily on spots where the bare mineral soil is exposed, 
or where the organic soil of entirely decomposed humus is near the 
surface; but a thick layer of undecomposed leaves or duff makes 
reproduction almost impossible. A ground fire which destroys the 
thick layer of undecomposed litter is very favorable to reproduction, 
provided seed is disseminated over the area after the fire and before 
brush and weeds have a chance to occupy the ground. 

Open situations, whether in the forest or on cleared areas, are 
most conducive to scrub pine reproduction. Germination from seed 
fallen in the open stands takes place under the same conditions as 
described for the broken forest, but the increased amount of light 
makes the seedlings more vigorous. On areas cleared by lumbering, 
pine seed germinates and the seedlings grow well, provided that there 
is not a dense growth of underbrush and weeds, or a thick layer of 
midecomposed litter. Fires after lumbermg, when they burn the 
tops, brush, and undecomposed litter, are very favorable for repro- 
duction. Keproduction from seed disseminated on idle farm land 
t)f all Idnds is uniformly good. Unused plowed land, with soil directly 
exposed, is most favorable. Pasture lands with a very compact sod 
are least favorable, but if they are grazed with sheep or hogs, which 
break the sod with their hoofs, the chances for reproduction are 
improved. In regard to fertility of the soil, scrub pine is very un- 
exactmg, as long as the soil is sufficiently loose to receive and retain 
the seed or if there are cracks and crevices to serve the same purpose. 

Where there are sufficient seed trees and favorable ground condi- 
tions an area will become well seeded in from three to five years. 

SEEDLING DEVELOPMENT. 

Scrub pine seedlings, once established, develop vigorously and rap- 
idly. The roots go deep in the first year. The young seedling is 
thoroughly frost-hardy, and can stand exposure not only to cold but 
also to direct heat from the sun's rays. 



14 



SCRUB PINE. 



The average rate' of growth of pine seedhngs which have abundant 
sunlight, is shown by Table 6. 

Table 6. — Height growth of scrub pine seedlings, Montgomery and Prince Georges Coun- 
ties, Md.'^ 



Age. 


Height. 


Age. 


Height. 


Years. 


Feet. 


Years. 


Feet. 


1 


0.9 


6.... 


7.8 


2 


2.0 


7.... 


10.5 


3 


3.2 


8.... 


13.2 


4 


4.6 


9.... 


15.0 


5 


6.0 


10.... 


17.0 



1 Based on measurements of 214 trees. 
ENEMIES. 

Injury to scrub pine, apart from that done m lumbering, comes 
most commonly through fire, wind, insects, and fungi. 

FIRE. 

Damage by fire varies with its nature and its severity, and with 
the age of the stand. In young seedling and sapling stands under 
15 feet in height, fires are usually severe surface and crown fires which 
kill the stand outright. Small pole stands with trees over 2 inches 
in diameter breast high are subject to severe surface fires, which have 
an injurious effect on the future growth of the stand, but seldom kill 
many trees. In such stands, even when they are very dense, crown 
fires, which would kill the trees outright, seldom occur. Surface 
fires in large pole stands and mature stands do not appreciably dam- 
age the gro\v'n. trees, as a rule, but they kill such pine reproduction 
as may be beneath them. The damage to single ti-ees from surface 
fires varies directly with the thickness of the bark. The thicker the 
bark, the better is the fire-resisting power of the tree. Table 8 shows 
the average thickness of bark on the radius for trees of different 
diameters. 



Table 8. — Average thickness of bark at 4-5 feet from the ground for trees of different 

diameters. 



Diameter 
breast 
high. 


Width of 
bark. 


Basis. 


Diameter 
breast 
high. 


Width of 
bark. 


Basis. 


Inches. 

1 

2 

3 

4 

5 

6 

7 


Inches. 
0.05 
.10 
.14 
.19 
.23 
.27 
.31 


Trees. 


Inches. 

8 

9 

10 

11 

12 


Inches. 
0.35 

.38 
.41 
.43 

.45 


Trees. 
13 
8 

5 


19 
28 
15 
41 
15 
20 




166 



ENEMIES. 15 

Scrub pine has the power of recuperating readily from damage by- 
fire, on account of resinous exudations which resist decay-producing 
agencies. 

WIND. 

Dense scrub-pirie stands are very subject to wind, sleet, and snow- 
break. Scrub pine on abandoned farm land where the upper soil 
has been cultivated usually develops a rather flat, wide, and fibrous 
root system 1 to 3 feet in depth, and the tree is therefore not very 
windfirm. The danger from windfall is greatest to trees developed 
ui dense stands, which are tall and have slender stems, and increases 
with the age of the stand. Unculled stands under 40 years of age 
are not much subject to windfall, but after that age the danger be- 
comes rapidly greater, and the opening up of stands by lumbering 
adds to this danger. Trees growing in open situations are usually 
windfirm. 

Great numbers of scrub pines throughout Maryland ' were overthrown by the gales 
accompanying the violent storm of March 3-4, 1909. Both sleet and snow fell during 
this storm, and their weight was probably an important factor in the destruction of 
the trees. In many places in Maryland the havoc wrought by this storm is still appar- 
ent. A large proportion of the trees was killed outright, being entirely uprooted; 
others are still living in an oblique position. 

Many large scrub pines were observed by the writer to have the young leaders broken 
off at their tops for a short distance, perhaps 2 or 3 feet. On examination these showed 
no evidence of fungous disease or insect injury, and the most natural conclusion is 
that the damage here is caused by ice and snow. Such injury of course opens up vul- 
nerable spots in the tree where insects or fungi may enter later. The weight of ice 
and snow may also often be a factor of considerable importance in the overthrow of 
the whole tree. 

INSECTS. 

As a rule damage to scrub pine from insects is slight. The fol- 
lowing statements concerning insect enemies of scrub embody 
information furnished by the Bureau of Entomology : 

The tree is liable to the attack of several species of insects through- 
out its natural range, and more particularly in the southern portions. 
The two most important of these belong to a class of bark beetles of 
the family Scolytidae. They are the destructive pine bark beetle 
Dendrodonus frontalis and the companion bark beetle Tomicus avulsus. 
Both of these species attack the inner bark and soon cause death. 
The prevalence of these insects varies from year to year, and m most 
cases of attack they destroy large areas of timber in one or two 
seasons, after which they perhaps disappear for a period of many 
years. 

Both species are usually found workmg together. Usually, but 
not always, the destructive pine bark beetle takes the lead, this 

J Observations by Arthur H. Graves, 1910. 



16 SCRUB PINE. 

depending upon the relative abundance of the two, as brought about 
by varying conditions. 

Pine trees that have been mjured by fire, wind, or hghtning are 
usually attacked by one or both of these beetles, and such trees often 
serve as breeding places from which swarms emerge to continue their 
devastations in healthy forests. Lightning-struck trees are par- 
ticularly subject to the attack of the destructive pine bark beetle, and 
in most cases when this insect is at all numerous, form a center around 
which a number of healthy trees are attacked and killed. Wind- 
felled trees and those scorched by fire are not so liable to attack by 
the destructive pine bark beetle and do not ofl'er so good an oppor- 
tunity for its increase. The companion bark beetle, which is much 
more common and generally distributed, is very often found breeding 
in these trees. 

FUNGI. 

The following statements in regard to fungi attacking scrub pine 
are based on information furnished by the Bureau of Plant Industry: 

The scrub pine is not subject to fungous diseases which threaten 
widespread destruction. The tree is so short lived that little oppor- 
tunity is afforded for the development of many of the fungous forms 
which attack other pines. Another reason for this comparative 
immunity may be that the tree is a specially vigorous species and 
can exude unusual quantities of resin that protects wounded surfaces. 

The three most important diseases ^ which attack scrub pme are the 
burl disease {Cronartium quercus), causing peculiar knots or swell- 
ings on branches and on the main trunk of trees ; the fungus Trametes 
pini, causing ''heart rot;" and a leaf-casting disease or pine-leaf 
rust, which results in premature loss of the needles. 

CHARACTERISTICS OF THE WOOD. 

APPEARANCE. 

Scrub pine has a light orange-tinged heartwood and a whitish 
sapwood. The wood is light, soft, and usually close-grained. It is 
difficult to distinguish the sawed lumber from that of shortleaf, lob- 
lolly, pitch, and other eastern yellow pines; but the sawmill men 
identify it by the following cJiaracteristics : Compact grain; large 
number of small, tight knots and rarity of large loose ones; small 
resin and pitch content; lightness in weight, and larger proportion of 
heartwood. These characteristics vary, however, and, as is the case 
with other eastern yellow pmes, it is often impossible to distinguish 
the wood with certainty. A detailed study of these pines by Prof. 
Filibert Roth failed to bring out characteristics which could invaria- 
bly be relied on. 

1 Observations by Arthur H. Graves, 1910. 



CHABACTEBISTTCS OF THE WOOD. 17 

MECHANICAL PROPERTIES. 

It is seldom possible to cut clear lumber, or lumber fit for planing, 
from scrub pine, since the wood is usually knotty and will make only 
common and box grades of rough lumber, for which no high teclmical 
qualities are essential. In mechanical properties, such as stiffness 
and strength, scrub pine ranks with other yellow pines; and where 
the trees are large enough it pays best to cut them into dimension 
timbers, in which use small, tight knots are not a serious defect. 

SEASONING. 

Scrub-pine lumber is usually cut from small and comparatively 
young trees, and for this reason shrinks and warps badly in seasoning. 
It warps less, however, than loblolly and pitch pine timbers from 
trees of the same diameter, for it is of slower growth and has a higher 
percentage of heartwood. In southern Maryland, where loblolly, 
pitch, and scrub pines frequently grow together in even-aged forests, 
the last is always preferred for timbers m local house framing, on the 
ground that it is more durable and less liable to warp. Usually, 
however, it is cut into framing and put into the house in a green, 
unseasoned state, in the belief that the green timbers can not then 
warp much out of shape. Time is allowed for the framing to season 
before the house is completed. In seasoning, the wood of any of the 
yellow pines may shrink 10 per cent in volume and increase from 50 
to 100 per cent in strength. 

DURABILITY. 

Scrub pine may be classed as a fairly durable pine. The heart- 
wood is much more durable than the sapwood. Saplings used as 
fence rails have a life of three years, while heartwood rails last from 
six to eight years. The heartwood of scrub pine makes durable fence 
posts, but the sapwood is of no value for this use unless treated with 
preservatives such as creosote. Scrub pine, where cut locally for 
house framing, is preferred for sills over loblolly and pitch pines 
because of its greater durability, due to the fact that trees large 
enough to be cut for sills are composed mostly of heartwood, while 
loblolly and pitch pines of the same size have a large proportion of 
sapwood. 

The best test of the durability of scrub pme has been its use for 
railroad ties. On a small branch division of the Pennsylvania Rail- 
road, running from Clayton, Del., to Oxford, Md., scrub pine has 
been used to some extent for ties. The oldest section boss on that 
division informed the writer that 22 years ago he laid 1,600 scrub- 
pine ties. After six or seven years most of these were taken out, but 



18 SCRUB PINE, 

not in an unsound condition; the narrow rim of sapwood had com- 
menced to peel off around the annual rings, and this badly littered 
up the track; but the heartwood of the ties was still perfectly sound. 
Two miles northeast of Greensboro the section boss showed two 
perfectly sound scrub-pine ties, composed entirely of heartwood, 
which had been put in the track 22 years before. There is no reason 
to question the record of the ties, since no more scrub-pine ties were 
used on this branch until two years ago. From this experiment it 
would seem that scrub pine makes a less durable tie than white oak, 
as durable a one as longleaf pine, and a more durable one than chest- 
nut. But it should be almost entirely heartwood cut from trees 70 
years of age and over. Scrub-pine ties are not adapted to main railroad 
lines, where there is constant and heavy freight traffic, because they 
do not hold spikes well enough. The wood is comparatively soft, so 
that the spike holes spread, especially on curves, where there is a 
heavy lateral impact against the rails. 

SUITABILITY FOR CHEMICAL FIBER AND GROUND-WOOD PULP. 

Since 1900 scrub pine has been rather extensively used in the 
manufacture of chemical fiber and ground-wood pulp. Two mills 
in Virginia use it in the mechanical or ground-wood process, and six 
or more mills in Pennsylvania, Delaware, and Maryland use it in 
the soda process, which produces chemical fiber. 

Scrub pine is not good for ground- wood pulp. As with other yellow 
pines, the grindstones and screens are gummed up by the pitch and 
resin, which also clog the cylinder and felt of the wet machine. The 
pulp produced is inferior in quality, is difficult to bleach, and dis- 
colors when exposed to the air and light. 

Yellow pines in general have twice as long fibers as those of most 
species, which is an extremely desirable quality for good chemical 
fiber. The high resin content is their chief drawback. Scrub pine 
is used with great success in the soda process, since the caustic 
soda extracts the resin and makes an excellent grade of chemical 
fiber. It is not suited to the sulphite process, because the sulphite 
solution is not strong enough to remove the resin. For chemical 
fiber scrub pine is superior to other yellow pines, because the wood 
is less resinous and for this reason does not require so strong a solu- 
tion of caustic soda or so mvich pressure; the manufacture, therefore, 
is less expensive and the fibers are less impaired. 

USES AND MARKET. 

The purposes for which scrub pine is used may be conveniently 
divided into two classes: (1) Those which use young stands of pine 
under 40 years in age, where there are few trees as large as 9 or 10 
inches in diameter breast high. This class includes the use of the 



USES AND MARKET. 19 

species for fuel, pulp wood, charcoal, excelsior, lagging (in mines), 
round fence rails, and small box lumber. (2) Purposes which require 
stands over 40 years in age, where there are many trees 10 inches 
and over in diameter breast high. Under this class comes the use of 
the species for lumber, railroad ties, piling, mine props, and split 
fence rails. 

The principal use to which the species is put is probably for fuel for 
local consumption. The largest use of the tree is in Maryland, where 
the relative quantity of scrub pine, in comparison with other species, 
is greatest. A close approximation of the yearly cut of scrub pine 
in that State is as follows: 

Cords. 

Pulp wood 20, 000 

Fuel (for shipment) 15, 000 

Charcoal 5, 000 

Lumber 2 24, OOO 

Miscellaneous 1, 000 

Total 55, 000 

Wliere the trees are large enough for saw timber it always pays 
best to cut scrub pine into lumber. The kinds of lumber cut from the 
species are: Dimension stuff, mainly for house framing; rough 
boards, for barn siding, fence boards, etc.; rough box lumber; hogs- 
head siding and heading; crating and heading; and staves for nail 
kegs. The cut of lumber is mostly used for boxes and crates. The 
cutting is done chiefly by portable mills, but to some extent by small 
stationary mills, and the output is, for the most part, used locally. 
The average value of scrub-pine lumber at the mills is about as 
follows : $12 per 1,000 feet for dimension stuff; $15 per 1,000 for boards 
8 inches or more in width; $10 to $12 per 1,000 for boards under 8 
inches in width; $8 to $9 per 1,000 for box lumber, crating, etc. 

Since most of the lumber cut is either for boxes and crates or for 
dimension or common boards for local consumption, little grading 
is done. As far as could be ascertained, the lumber is never kiln- 
dried to be graded and to pass inspection under the North Carolina 
Pine Association rules. It is possible, however, that where it occurs 
in mixture with loblolly and shortleaf pines in southern Virginia 
and North Carolina it is sometimes cut and graded as "North Caro- 
lina pine," but it would seldom grade better than No. 3 (No. 1 Com- 
mon) or Box. 

Scrub pine is used locally for kindling and firewood, and is also 
shipped extensively to towns and cities, especially to Washington, 
Baltimore, and Philadelphia. The price f. o. b. local stations is 
$2.50 to $3 a cord and delivered in towns and cities it brings $3.50 
or more per cord. In Washington the dealers pay $4 to $5 per cord 

1 Several times tliis amount used locally. 2 Equal to 12,000,000 board feet. 



20 SCRUB PINE. 

delivered, and in Philadelphia $5 per cord and even higher. In 
common with other yellow pines, it is especially valuable for kindling 
wood. 

Charcoaling is carried on extensively in southern Maryland and 
by several operators on the Eastern Shore of Maryland. It is done 
entirely in charcoal kilns, locally known as pits. The following 
figures on the charcoal industry refer to southern Maryland : From 5 
to 25 cords of wood are stacked in a kiln, with an average of about 10 
cords, and 40 bushels of charcoal are obtained per cord of wood. 
This charcoal is generally sold in carload lots to city merchants, and 
brings, on an average, $125 per carload of 1,300 bushels, f. o. b. 

The use of scrub pine for paper pulp has already been mentioned. 
Its most extensive use for this purpose is by mills in southeastern 
Pennsylvania and eastern Maryland. In 1908 about 30,000 cords 
of scrub pine were used for pulp, with an average cost per cord, f. o. b. 
mill, of $6.60. This cost per cord may be roughly divided as follows: 

Stumpage $0. 50 to $1. 50 

Felling, peeling, and stacking 1. 25 

Hauling 1. 00 

Loading on cars .25 

Freight 2. 50 to 2. 00 

Contractor's profit 1. 10 to .60 

Total 6. 60 

The supply comes entirely from old-field growth of scrub pine, 25 
to 50 years old, which has come up since the Civil War. The trees 
are felled, the branches are cut off, the bark is peeled, and the stems 
are sawed into 5-foot lengths. The peeling is done in the spring 
with a barking iron or "spud," and at other seasons with a drawknife. 
The whole stem is taken, down to about 2 inches inside the bark, 
but trees less than 5 inches in diameter, breast high, are seldom cut. 

The stumpage, the value of standing scrub-pine timber, varies 
with the locality and size of the timber. The highest stumpage 
values that were noted were in southern New Jersey, in the vicinity 
of Millville and Bridgeton— $1 per cord for cord wood and $3 per 
1,000 for saw timber. In Pennsylvania 50 cents to $1.50 per cord is 
paid for stumpage for pulp wood. In southern Maryland 50 cents 
to $1 is paid for cord wood stumpage, and $2 to $4 per 1,000 for saw 
timber. Farther southward stumpage values gradually decrease, and 
in North Carolina they are very low. 

ADVISABILITY OF FOREST MANAGEMENT. 

Silviculturally, scrub pine is excellently fitted for forest manage- 
ment for two reasons: First, because it occurs so largely in pure, 
even-aged, fully stocked stands, the most simple form of forest for 



PUEPOSES OF MANAGEMENT AND ROTATION. 21 

management; and second, because of the ease with which the estab- 
hshment of a new crop by natural reproduction can be secured after 
the removal of the mature stand. 

Forest management of pure second-growth stands of scrub pine 
to secure successive crops of timber is advisable on land of little value 
for agricultural or other purposes. It is also desirable to perpetuate 
the species where growing in mixture with hardwoods in the farmer's 
woodlot, provided there are no more valuable species of pine in the 
mixture which should be given preference. Scrub pine, furthermore, 
does good service in the renovation of worn-out agricultural land, 
and where trees of the species are sufficiently near they can be 
advantageously allowed to seed up such land and a crop of timber 
grown wliile the soil is being enriched. 

By exercising a little care in cutting a mature stand of pure scrub 
pine, it will be possible under favorable conditions to procure a good 
stand of young-pine seedlings, wliich in 30 years will yield a crop of 
26 cords of pulp wood to the acre, or if left 50 years will cut 17,700 
board feet of 1-inch box boards per acre. The pulp wood should be 
worth in many places, at present prices, $1 a cord on the stump, or S26 
per acre, and the box boards $2.50 per 1,000 on the stump, or $44.25 
per acre. 

As the timber supply of the United States is continually decreas- 
ing, it is reasonable to expect that stumpage prices in 30 to 40 3^ears 
will be higher than these values, and the profits to be derived from 
forest management greater than present stumpage prices would seem 
to indicate. 

PURPOSES OF MANAGEMENT AND ROTATION. 

Before a system of management is decided upon it is necessary to 
decide the purpose for which the timber is to be grown. If it is for 
large stuff, such as saw timber, railroad ties, etc., more than 40 years 
will be recpiired to grow a crop; if it is for small-sized material, such 
as pulp wood, charcoal, or fuel, the timber will be ripe in less than 40 
years. Silviculturally and financially, a short rotation for scrub pine 
is more advisable than a long one. After 50 years the stand becomes 
more and more open, and the consequent increase of underbrush and 
weeds makes natural reproduction more difficult; also, with increas- 
ing age, the danger from snow and windfall becomes constantly greater 
and the tree is more likely to become attacked by insects and disease. 
Sixty to seventy years should, therefore, be considered, as a rule, the 
maximum rotation for scrub pine. 

Table 9 shows the current amiual increment and the mean annual 
increment for pure second-growth, fully stocked stands of scrub pine ; 
or, in other words, the added volume put on during the last year at each 
stated age and the average for each year it took to attain that age. 



22 SCRUB PINE. 

Table 9. — Mean and current annual increment for fully stocicea stands of scrub pine- 





Mean 


Current 




Mean 


Current 


Age. 


annual 


annual 


Age. 


annual 


annual 




increment. 


increment. 




increment. 


increment. 


Years. 


Cords (fuel). 


Cords (fuel). 


Years. 


Cords (fuel) 


Cords (fuel). 


15 


0.85 


1.75 


35 


0.99 


0.91 


20 


1.00 


1.23 


40 


.97 


.84 


25 


1.00 


.98 


45 


.95 


.75 


30 


1.00 


.94 


50 


.93 


.65 



Tliis shows that the most profitable rotation would be between 
30 and 40 years, during which period the mean annual increment 
continues high. Before 30 years many trees in the stand are too 
small to make cutting desirable. 

SUSTAINED ANNUAL YIELD. 

To procure a sustained annual yield in pure scrub-pine forests is a 
comparatively easy matter. For example, if the woodlot owner 
desires to cut 100 cords annually for fuel, charcoal, or pulp wood from 
a pure pine forest to be managed on a 30-year rotation, where the 
average mean annual increment for the rotation is 1 cord per acre per 
annum, it would simply be necessary for him to clean-cut 3^ acres a 
year of 30-year-old pine and reproduce this area. This would require 
a total of 3jx30, or 100 acres of land, for a sustained annual yield 
of 100 cords on a 30-year rotation. 

If there is not an even distribution of age classes, from 1 to 30 years, 
to start with, tliis distribution will be secured at the end of the first 
rotation by cutting and reproducing 3^ acres each year. An irregular 
distribution of age classes naturally causes an irregular yield from the 
cuttings for the years of the first rotation. The 3 J acres to be cut 
annually need not necessarily be in one body, but may be located in 
several different parts of the forest in order to facilitate reproduction. 

The acquisition and management of forest land to supply a sus- 
tained annual yield is especially advisable for manufacturing concerns 
requiring a continuous yearly supply of wood. In regard to scrub- 
pine land, such a policy will often be advisable in the case of pulp 
companies, provided the land without the timber is sufficiently low 
in value. Both the land and the timber can often be bought for the 
price paid for the stumpage alone, and it is especially advisable for 
pulp companies using scrub pine to acquire cheap land for growing 
their supply of pulp wood. 

NEW CROPS BY NATURAL REPRODUCTION. 

Good natural reproduction of scrub pine in pure stands is best 
secured by nearly clean cuttings which leave from 5 to 10 seed trees 
to the acre. The trees selected to remain should be such as have the 



NEW CROPS BY NATURAL REPRODUCTION. 23 

best-developed crowns or are already full of cones, and should be 
evenly distributed over the area. Stands under 40 years of age, 
wliich are still very dense, will not produce much seed until the second 
or tliird year after cutting, but the isolated trees remaining should 
then bear profusely. A heavy thinning of a dense stand several years 
before the final cutting should considerably increase the amount of 
seed produced and is recommended where it will pay. The seed 
trees left can be cut and removed, if desired, as soon as the area is 
sufficiently stocked with seedlings, but special care must then be 
taken to keep fires and other sources of injury away from the young 
gro\ving stock. Otherwise the seed trees mil be left to develop into 
large timber trees. 

Where it is desired to cut clean and it is not practicable to leave seed 
trees to be later removed, it is possible to obtain natural reproduction 
by cutting in strips. In this case the seed will be disseminated by 
the wind over the cleared strip from the border trees of the remaining 
stand, but the reproduction will not be so well distributed as in the 
scattered seed-tree method. It is best not to make the strips more 
than 100 feet wide, and they should always be cut on the leeward side 
of the stand and progress toward the direction from which the pre- 
vailing winter winds blow. From two to five years should elapse 
between the cutting of adjacent strips in a stand, so that each strip 
may be well reproduced from the neighboring stand. 

It may sometimes be desirable to work a combination of the 
scattered seed tree and the strip methods. For instance, where it is 
wished to cut a much wider strip than 100 feet scattering seed trees 
may be left on the outermost part, wliile the part nearer the standing 
timber may be cut clean. 

The principal obstacles to reproduction after cutting are: First, 
branches and tops left after lumbering; second, too thick a ground 
cover of undecomposed forest litter; and third, undergrowth, hard- 
wood sprouts, and weeds. Usually, it will not be advisable to expend 
much money to overcome these hindrances, but much good can be 
done ^xith. only a small expenditure if it is carefully applied. In lum- 
bermg, it is well to pile the brush in narrow rows to take up the least 
possible ground space; tliis will also make the handling and trans- 
portation of the timber more convenient. Agaui, in logging opera- 
tions, the more the soil is wounded and the undecomposed litter dis- 
turbed the better it is for the seed. The most effective instrument 
for improving the seed bed is fire, which, however, must be very care- 
fully handled. It is always a good plan to burn the brush, after it 
has been carefully piled in heaps, for this complete destruction of the 
brush will be of great benefit. Where the undecomposed htter is 
especially thick, it is beneficial to burn the entire cut-over area with 
a ground fire, which destroys brush and litter, as well as undergrowth 



24 SCRUB PINE. 

and weeds. Such a burning had best take place in the fall of the 
year and when it is seen that the seed trees are full of cones from 
which seed will be scattered over the area in abundance the following 
year. Care should be taken to prevent the fire from spreading into 
adjacent standing timber, and especially into recently reproduced 
stands. The brush should be carefully raked from around the seed 
trees, in order to prevent damage to them. 

Where scrub pine occurs mixed with hardwoods, as it often does in 
woodlots, it can best be maintained by making openings in the forest 
around pines which are good seeders, the size of these openings to be 
gradually increased as the pine reproduction springs up. In a mixed 
hardwood-sprout forest, managed on a clean cutting system, it will be 
necessary to get the pine started by tliis method of making openings 
several years before the clean cutting takes place, as the dense and 
rapid growth of sprouts after cutting would otherwise prevent the 
reproduction of pine. 

IMPROVEMENT THINNINGS. 

The object of thinning is the improvement of the growing condi- 
tion of the stand before it is ripe for the final cutting, by the removal 
of a portion of the trees in stands too dense for the best development 
of the stand as a whole. In scrub pine stands tliinnings are recom- 
mended only where they will yield a net return m money on the wood 
removed, or will at least pay for the work done. 

The trees to be removed in tliinnings can best be indicated by the 
following classification of trees composing stands : 

(1) Dominant and codominant classes. Trees which make the 
upper crown cover, (a) Dominant— trees with well-formed crowns. 
(b) Codominant — trees "wdth uneven crowns. 

(2) Intermediate and suppressed classes. Overtopped trees which 
have fallen in growth below the upper crown cover, (a) Intermedi- 
ate trees — with crowns free to light, (b) Suppressed trees — with 
crowns directly shaded but thrifty. 

(3) Dying or dead. 

The object of the thinning should be to favor trees of the dominant 
class by the removal of trees of other classes wliich are liindering their 
proper development, and wliich will be mainly codominant and inter- 
mediate trees. Codominant trees should be favored over interme- 
diate and suppressed trees. A moderate tliinning will consist of the 
removal of all iatermediate and suppressed trees, wliile a heavy thin- 
ning will include many codominate trees. Diseased and djing trees 
of any class and dead trees should always be removed. 

In very dense stands early tliinnings, even before 20 years of age, 
are especially helpful, but are often very difficult to make. It will be 
best in such thick young growth not to try to make regular tliinnings, 



EXTENSION. ' 25 

but simply to cut parallel straight lanes through the stand about 5 
feet in width and at intervals of about 10 feet, with a maximunr re- 
moval of one-third of the stand. The clear cutting of lanes in this 
manner makes it possible to fell trees with comparative ease, while 
with a selective method it would be a case of continual and difficult 
lodging and hanging. 

PROTECTION. 

Harm from insects and diseases can be combated by cutting out 
all infested and diseased trees in the fall and winter, and stripping off 
and burning the bark, as well as the branches and tops, to destroy the 
insects or fungi, and thus prevent the infection of other trees. It is 
possible to cut scrub stands without danger from insect infestation to 
trees left by doing the cutting some time between November and 
April, and burnmg all slash left after cutting. 

Danger from windfall is lessened by cutting toward the prevailing 
wind, as recommended in the strip method of cutting. The shorter 
the rotation, the less will be the danger of windfall. Scattered seed 
trees will always be in danger from windfall. A thinning previous to 
the final cutting would not only increase the seed production of the 
remaining trees, but also cause them to develop more wind-firm root 
systems, so that the trees selected for seed would be less subject to 
windfall. 

Fire is by far the most important cause of damage to the forest, 
and the one most necessary to be guarded against. The greatest 
injury by fire is to young seedling and sapling stands, which are often 
killed outright, and these are therefore in need of protection from 
fire. The larger the stand, the less it is liable to serious injury by 
fire; but it is always best that fire be kept out entirely from stands 
of all ages and sizes. 

Fire patrols should be maintained, especially in the spring before 
the leaves come out and in the autumn after the leaves have fallen, 
and all fires should be put out as soon as found. Since the forests 
of scrub pine occur so largely in small areas, broken up by fields and 
roads which act as barriers, extensive fires are rare. 

EXTENSION. 

Scrub pine extends naturally over unused fields wherever seed 
trees are in the vicinity, and it is often advisable to allow it to take 
possession of worn-out farm land. But where it is wished to extend 
the forest artificially, it will pay best in most cases to grow some 
more valuable species than scrub pine. On bare, sterile soils, how- 
ever, not well suited to the growth of better species, it may be well to 
sow scrub pine, which thrives where many other species would fail. 
Again, when seed can be easily and cheaply collected, artificial 



26 SCRUB PINE. 

sowing may be used to help out the natural extension over pastures 
and fields. It is probable that sowing in seed spots will be successful 
with this species, which would be cheaper than planting. The 
seed spots should be about 1 foot square, and well grubbed up so as 
to expose and pulverize the surface soil, and to make it loose to a 
depth of several inches. Three to five seeds should be sown in a spot, 
covered to a depth of one-eighth to one-quarter of an inch, and 
stepped on lightly with the ball of the foot. To produce well- 
stocked stands the spots should not be more than 6 feet apart. The 
sowing should be done in spring, after the buds of the trees begin 
to swell. Fall or winter sowing gives the seed a longer time in 
which to deteriorate. Transplanting of wild stock 1 to 2 years old 
may be practiced in some cases successfully and cheaply. 

PREVENTION OF EXTENSION. 

Wherever it is associated Avith shortleaf or with white pine, scrub 
pine tends to replace them in the second growth, after lumbering. 
In such cases it is advisable to eradicate scrub pine by carefully cut- 
ting out all trees of the species which are bearing or are likely soon 
to bear seed, and by leaving seed trees of shortleaf or of white pine 
to restock the cut-over area. Scrub pine should be allowed to extend 
itself only where it is not possible or practicable to secure reproductiom 
of more valuable species. 

SUMMARY. 

The species is especially .adapted to sterile soils and worn-out 
farm land. It occurs principally on idle farm land, where it fre- 
quently forms pure, even-aged, fully stocked stands. It is a fairly 
rapid grower in early years, but as a rule is short lived, and does not 
reach large dimensions. It reproduces itself with the utmost ease, 
and rapidly extends itself over idle cleared land wherever seed trees 
are at hand. 

Since the prevailing growth of the species is small, the wood is 
principally used for fuel, pulp wood, and charcoal. Wlierever it is 
large enough, it is cut for lumber for local consumption, which is 
the most profitable use for such timber. Trees of the species which 
have come up in open stands have little value; the growth must be 
in fairly dense stands to be of commercial value. The species is 
better adapted for pulp wood than are the more resinous yellow pines. 
It has also been successfully used for railroad ties, and could be 
greatly improved for this purpose by creosoting, to which it is very 
well adapted. 

Forest management, as a rule, is advisable for pure second-growth 
scrub-pine land, where the land is of little value for agricultural or 
other purposes. Such stands can be easily reproduced, and yield a 



SUMMAEY. 27 

fair revenue after cutting. Wliere mixed with hardwoods it is a good 
tree to maintain on the woodlot, provided there are growing no more 
valuable species of pine to be encouraged. A short rotation of 30 to 
40 years is silviculturally and financially preferable to a long one. 
Scrub pine is adaptable to management for a sustained annual yield. 
Improvement thinnings are advisable wherever they can be made to 
pay for themselves. The natural or artificial extension of scrub pine 
over additional areas of worn-out farm land or barren land is some- 
times advisable where seed trees are abundant and natural seeding 
will take place, or seed can be collected at small cost, and where it 
would be difficult or too expensive to secure the growth of better 
trees. On the other hand, where scrub pine competes with more 
valuable species for occupation of the soil, as it does with shortleaf 
pine in parts of Virgima, it should be eradicated as much as possible 
and prevented from seeding up cut-over areas or abandoned agri- 
cultural land. 

o 



